Bump log from 0.4.19 to 0.4.21

Bumps [log](https://github.com/rust-lang/log) from 0.4.19 to 0.4.21.
- [Release notes](https://github.com/rust-lang/log/releases)
- [Changelog](https://github.com/rust-lang/log/blob/master/CHANGELOG.md)
- [Commits](rust-lang/log@0.4.19...0.4.21)

---
updated-dependencies:
- dependency-name: log
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

Cargo.toml

@@ -11,7 +11,7 @@ anyhow = "1.0.79"
 async-trait = "0.1.48"
 config = "0.14.0"
 futures = "0.3.29"
-log = "0.4.19"
+log = "0.4.21"
 pretty_env_logger = "0.5.0"
 serde = { version = "1.0.196", features = ["derive"] }
 serenity = {version = "0.10.10", default-features = false, features = ["client", "gateway", "rustls_backend", "model"]}